CAN COMMUNICATION SYSTEM(for RHD) Air Conditioning Amplifier Communication Stop Mode

DTC Code DTC Name
Air Conditioning Amplifier Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Air Conditioning Amplifier Communication Stop Mode

Either condition is met:

  • "Air Conditioning Amplifier" is not displayed on "CAN Bus Check".

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  • Communication system DTCs (DTCs that start with U) that are output correspond to "Air Conditioning Amplifier Communication Stop Mode" in "DTC Combination Table".

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  • Power source or inside air conditioning amplifier assembly

  • Air conditioning amplifier assembly CAN branch wire or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM

C250981E42
C277463E05

CAUTION / NOTICE / HINT

Note:

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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  • Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

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  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • DTC check procedure: Turn the ignition switch to ON and wait at least 11.6 seconds.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed.

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Tip:

  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

PROCEDURE

  1. CHECK FOR OPEN IN CAN BUS WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY CAN BRANCH WIRE)

    1. C277462C01

      *A

      for Automatic Air Conditioning System

      *B

      for Manual Air Conditioning System

      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the cable from the negative (-) battery terminal.

    2. Disconnect the air conditioning amplifier assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Table 1. for Automatic Air Conditioning System

      Tester Connection

      Condition

      Specified Condition

      G81-11 (CANH) - G81-12 (CANL)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω
      Table 2. for Manual Air Conditioning System

      Tester Connection

      Condition

      Specified Condition

      G80-8 (CANH) - G80-9 (CANL)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY CAN BRANCH WIRE OR CONNECTOR (CANH, CANL)

    OK

  2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BATTERY AND BODY GROUND)

    1. C277462C02

      *A

      for Automatic Air Conditioning System

      *B

      for Manual Air Conditioning System

      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Connect the cable to the negative (-) battery terminal.

      Note:

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Table 3. for Automatic Air Conditioning System

      Tester Connection

      Condition

      Specified Condition

      G81-21 (B) - Body ground

      Always

      11 to 14 V

      G81-1 (IG+) - Body ground

      Ignition switch ON

      11 to 14 V
      Table 4. for Manual Air Conditioning System

      Tester Connection

      Switch Condition

      Specified Condition

      G80-1 (IG+) - Body ground

      Ignition switch ON

      11 to 14 V

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Table 5. for Automatic Air Conditioning System

      Tester Connection

      Condition

      Specified Condition

      G81-14 (GND) - Body ground

      Always

      Below 1 Ω
      Table 6. for Manual Air Conditioning System

      Tester Connection

      Condition

      Specified Condition

      G80-23 (GND) - Body ground

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

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    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR